Electric equipment mounted to an automobile or the like is connected to other electric equipment or a power device via wire harnesses that include insulated wires in a bundle, forming an electric circuit. The wire harnesses and electric equipment or the power device are connected through connectors attached thereto.
Various crimp terminals provided in the connectors described above have been proposed, and the crimp terminal disclosed in Patent Document 1 is one such crimp terminal.
A crimp terminal 81 disclosed in Patent Document 1 is a closed-barrel type crimp terminal 81 as illustrated in FIG. 14, wherein a conductor 83 exposed on a tip side of an insulated wire 82 is inserted into a crimping portion 81a having a substantially cylindrical shape of the crimp terminal 81, and then the crimping portion 81a is deformed in a contracting direction and crimped and connected to the conductor 83.
However, when the crimping portion 81a having a substantially cylindrical shape such as described above is deformed by a lower blade 71 and an upper blade 72 of a crimping device 70 illustrated in FIG. 14A, for example, the lower blade 71 and the upper blade 72 are point-contacted in a radial direction to an outer periphery of the crimping portion 81a to pressurize, causing an increase in the level of difficulty in aligning a crimping direction Z in which the lower blade 71 and the upper blade 72 pressurize the crimping portion 81a with a vertical virtual reference line that passes through a center portion P in a radial direction of the crimping portion 81a, in proportion to a circularity and a hardness of the crimping portion 81a, and the crimping portion 81a to rotationally move in a direction illustrated by a long dashed double-short dashed line in FIG. 14A by just a slight horizontal displacement of the center portion P in the radial direction of the crimping portion 81a. As a result, when the crimping portion 81a is deformed, twisting readily occurs on the crimping portion 81a, and the crimping portion 81a cannot be crimped and connected in the desired crimping shape (refer to FIG. 14B).
Further, when twisting occurs on the crimping portion 81a, stress collects in the twisted portion, causing an increase in the possibility of breakage, cracks, and the like, and resulting in the concern that the desired connection strength cannot be ensured. Furthermore, with the twisting of the crimping portion 81a, a portion of the crimping portion 81a protrudes significantly toward a direction perpendicular to a longitudinal direction of the crimping portion 81a. When the protruding portion protrudes a large amount and the crimp terminal 81 to which the insulated wire 82 is connected is inserted into a terminal insertion hole of a connector, the protruding portion of the crimping portion 81a abuts against an area near an inlet or an inner wall of the terminal insertion hole, hindering insertion. This hindering insertion makes it difficult to insert the crimp terminal 81 to a predetermined position inside the terminal insertion hole, and causes the insertion properties of the connector into the terminal insertion hole to deteriorate.